Room air conditioner condensate sump



Nov. 10, 1959 s. L. 'MCMILLAN 2,911,800

ROOM AIR CONDITIONER CONDENSATE SUMP Filed Oct.

F'IGJ INVENTOR.

H15 ATTORNEY United States Patent 2,911,800 ROOM AIR CONDITIONERCONDENSATE SUMP Stephen L. McMillan, Jetfersontown, Ky., assign'or toGeneral Electric Company, a corporation of New York Application October27, 1958, Serial No. 769,652

4 Claims. (Cl. 62-280) The present invention relates to a room airconditioner and more particularly to a condensate water drainarrangement for the sump of such air conditioner which at some timemight be exposed to freezing weather conditions.

Air conditioners of the self contained type usually comprise a casing orhousing having a partition or barrier dividing the easing into inner andouter compartments, the inner compartment intended to be located in anenclosure (room) and the outer compartment outside the room. These unitsemploy a refrigerating apparatus including at least two heat exchangers,one located within the inner compartment and the other located in theouter compartment which is exposed to the outdoor air.

Fans are provided in the compartments for circulating air through therespective compartments and over the heat exchangers mounted withinthem. In a typical arrangement, the fans are mounted on a common driveshaft extending through the partition and driven by an electric motorwhich is usually mounted on the partition. Some of these airconditioners employ a refrigeration system of the reversible type havingheat exchangers which are interchangeably operable either as a condenseror an evaporator to both heat and cool the enclosure. The apparatus isprovided with a sump located beneath the heat exchanger in the outercompartment and means are provided for collecting condensate water fromeither of the heat exchangers and delivering the water to the sump inthe outer compartment. In order to dispose of the condensate watercollecting within the sump, many conditioners provide a slinger ringattached to and surrounding the periphery of the outdoor fan. Theslinger ring extends or dips into the condensate water in the sump and,during rotation throws the water out of the sump onto the outside heatexchanger where it is either evaporated into the air stream or carriedin small droplets by the air stream out of the unit.

During the winter months, when using this type of slinger ring, there isa possibility that it might become solidly frozen within the condensatewater if the outside temperature drops below freezing. If the condensatewater in the sump freezes around the slinger, then when the conditioneris turned on, the fan cannot rotate, and this causes the fan motor tooverheat or results in some other serious damage to the mechanical partsof the unit. Means must be provided, therefore, to eliminate the dangerof ice forming around the slinger ring when the outdoor temperaturedrops below freezing.

Accordingly it is an object of the present invention to provide animproved condensate water drain arrangement for disposing of thecondensate water which collects in the sump of an air conditioning unitwhen the outdoor temperature approaches the freezing point of water.

Further objects and advantages of the invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize the invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

In carrying out the present invention there is provided an airconditioning apparatus having a compressor and a pair of heatexchangers, one of which it mounted in a compartment exposed to indoorair and the other being mounted in a compartment exposed to outdoor air.A condensate sump is provided beneath the outdoor heat exchanger andmeans are provided for conducting condensate water forming on either ofthe heat exchangers to the condensate sump. In order to dispose of thecondensate water in the condensate sump when the outdoor temperaturedrops below a predetermined temperature, there is provided a drain meansin the bottom of the sump comprising a thermally responsive disk havinga drain hole centrally located on the disk. The outer edge of the diskis mounted in water tight sealed relation with the edges of an openingin the bottom of the sump. When the outside temperature is above apredetermined temperature the disk is flexed so that its centralportions are flexed in the upward direction so that the drain hole ismaintained a distance above the bottom of the sump .thereby preventingthe water from flowing through the drain hole. When the outdoortemperature falls below a predetermined temperature the disk flexesdownwardly to a concave position so that the drain hole of the disk isbelow the level of the bottom of the sump for draining the condensatewater out of the sump.

For a better understanding of the invention reference may be had to theaccompanying drawing in which:

Fig. 1 is a vertical side view in section of an air conditioningapparatus incorporating the present invention;

Figs. 2 is a fragmentary enlarged elevation view, partially in section,showing the improved drain arrangement.

Referring now to Fig. 1 there is shown an air conditioner of thereversible refrigerant flow type which is arranged to be positionedwithin an opening in an enclosure. The unit comprises a casing 2 whichis divided by a barrier 3 into an inner compartment 4, within which anindoor heat exchanger or evaporator 6 is mounted, and an outercompartment 7, containing an outdoor heat exchanger or condenser 8. Theheat exchangers 6 and 8 are connected in refrigerant flow relationshipwith a compressor 9 also positioned in the outer compartment 7. Theconditioner is provided with a reversing valve 11 which may beselectively operated to reverse the flow of refrigerant to the heatexchanger units 6 and 8. When the conditioner is on the cooling cycle,air is drawn from within the room by an air moving means or fan 12 andpassed over the heat exchanger 6 which is operated as an evaporator.During operation of the unit on a cooling cycle, the moisture from theroom air condenses onto the coil surfaces of the heat exchanger anddrains downwardly where it is collected in a suitable drip tray 13. Thecondensate water is delivered from the drip tray 13 by means of aninsulated conduit 14 to a condensate collection sump .16 formed in thebase of the unit in the outer compartment 7 of the conditioner. I

As shown in Fig. 1, an air moving means or fan 17 is disposed in theouter compartment and is driven by a shaft 13 from a motor 19 mounted inthe barrier 3. When the unit is on the cooling cycle, the fan 17circulates outside air over the heat exchanger 8 to remove the heat fromthis heat exchanger, which is operating as a condenser. Morespecifically, the fan 17 pulls outside air through the inlet opening 20,blowing it inwardly against the barrier 3 whereupon it flows upwardlythrough the heat exchanger 8 and is then discharged through the outletopening 21. When the unit is operating on the heating cycle, thereversing valve 11 reverses the flow of refrigerant to the heatexchangers 6 and 8 thereupon utilizing the heat exchanger 6 as acondenser and heat exchanger 8 as an evaporator. During ing point ofwater.

slinger ring. below the predetermined temperature, the bimetal diskroom. The outer compartment heat exchanger 8 condenses moisture out ofthe air. duringthe heating cycle and this moisture also. collects in thecondensate collectionsump i6.

Mounted on. the extremeties of the fan 17 is aslinger ring 22 whichextends .downwardlyinto the space. defined by the sump 16 and is atleastpartially submerged in the condensate water collected therein. As thefan rotates, water is picked up by the slinger ring and thrown bycentrifugal force onto other parts of the outdoor compartment and, morespecifically onto the heat exchanger 8. During the cooling cycle whenthe heat exchanger 8 is acting as a condenser, the condensate waterthrown onto this heat exchanger vaporizes and cools the heat exchangerthereby increasing its capacity and the capacity of the refrigerationsystem as a whole. As thus far described, this air conditioner with itsreversible heat exchanger system forms no part of the present invention,but is intended only to be illustrative of one type of air conditionerto which this invention is particularly well adapted. It is not intendedto limit the invention only to air conditioners of the reversiblerefrigerant flow type, as the invention is also very useful in theordinary type of air conditioner which may be permanently mounted in thewall of a room and used during the cooler months of the year to provideventila- -tion or to exhaust air from the room. As will now bedescribed, the invention deals with a means for draining condensatewater'from the sump'when the outdoor temperature drops below apredetermined temperature.

In order to dispose of the condensate water in the condensate, sump 16the present invention provides a drain means which operates to drain thewater out of the sump whenever the outdoor temperature approaches thefreez- Mounted in the bottom of the sump, is a thermally responsivebimetal disk 24 that occupies the upwardly curved or convex shape, shownin solid lines in Figs. 1 and 2, when the temperature is above apredetermined temperature such as 36 F. The disk occupies the downwardlycurved or concave shape, shown in dotted lines in Fig. 2, when thetemperature falls below the above mentioned predetermined temperature.The bimetal disk 24 is mounted in an opening in the bottom of the sumpand is retained in water tight sealed relationship therein by means of aflexible or resilient gasket 26, which surrounds the entire outerperimeter of the disk 24. Thegasket 26, in turn, is connected in sealedrelationship to the edge 27 of the opening. The gasket permits the outerperimeter or edge of the bimetal disk to move slightly with respect tothe edge 27 of the opening and allows the-disk to flex or move from oneposition to the other during changes in the temperature.

Centrally located on the disk is a drain hole 23 which is held a shortdistance above the bottom of the sump and above the lowermost edge 22aof the slinger ring 22 when the bimetal disk is flexed in the convexposition shown in solid lines in Fig. 2. That is, whenever thetemperature is above the predetermined temperature, the disk holds thedrain hole above the bottom of the sump and above the edge 22a of theslinger ring. In this manner, whenever the outdoor temperature is abovethe predetermined temperature (such as 36 F), the condensate water-ismaintained at a level in the sump 16 so that it is picked up and slungout of the sump by the Whenever the outdoor temperature falls flexes tothe dotted line position shown in Fig. 2 and moves the drain hole 28below the level of the bottom of the sump thereby causing the condensatewater to drain through the hole 28. It should be pointed out that thebimetal disk can be provided which accurately moves between two flexedpositions within two or three degrees of any desired temperature. Means(not shown) can be provded beneath thedrain hole for carrying the con-.fimn ear nteeay .d iisfdil'sa sn 9 e Wi s?" be positioned such that thewater drains directly onto the ground outside the b ilding.

The. dr in 1101 2 lnlthe disk also acts as an overflow hole; wheneverconditions are such that an excessive amount of water is condensed outof the air and this maintains thewater at a safe level in the sump. Itpermits the water to overflow'and drain to the outside, preventing waterfrom flowing into other portions of the unit or possible overflowingonto the floors of the enclosure.

By the present invention there has been provided a condensate sump drainarrangement for an air conditioning unit which operates to dispose ofthe condensate water when ever the outside temperature drops below apredetermined,level. Moreover the drain is initiated automatically by.the..lowering of the outdoor temperature and requires no other type ofcontrol.

While in accordance with the patent statutes there has been describedwhat is considered to be the'preferred embodiment of the invention, itwill be obvious to those skilled in the art that various changesandmodifications may be made therein without departing from the inventionand it is therefore the aim of theappended claims to" cover all suchchanges and modi fications.that fallwithin the true spirit and scope ofthe invention.

.tion with the edge of the opening, said disk having a drain holepositioned adjacent the central areathereof, said disk being flexedupwardly with respect to the bottom of said sump when the temperature ofthe outside air is above a predetermined temperature so that said drainhole is maintained above the bottom of said sump to prevent the waterfrom flowing through said drain hole, said disk flexing downwardly withrespect to the bottom of said sump. when the temperature of the outsideair falls below the predetermined temperature so that said drainhole isdisposed beneath the level of the bottom of said sump to permitcondensate water to drain through said drain hole.

2. In combination with a self-contained air conditioner having acondensate water collection sump exposed to outside temperatureconditions and including a rotatable water slinger dipping into saidsump, drain means in the bottom of said sump including a thermallyresponsive disk mounted in an opening in the bottom of said sump,

perature of the outside air is above a predetermined temperature so thatsaid drain hole is maintained a distance above the bottom of said sumpto retain condensate water in said sump, said disk being flexeddownwardly with respect to the bottom of said sump when the. temperatureof the outside air is below said predetermined temperature, so that saiddrain hole is disposed beneath the level of the bottom of said sump topermit condensate water to drain through said drain hole.

3. In combination with a self-contained air conditioner having acondensate water collection sump exposed to outdoor temperatureconditions and including a rotatable water slinger dipping into saidsump, drain means in the bottom of said sump comprising a thermallyresponsive bimetal disk mounted in an opening in the bottom of saidsump, a flexible sealing gasket connected between the outer perimeter ofsaid bimetal disk and the inner edges of said opening in the bottom ofsaid sump, said flexible gasket permitting the outer perimeter of saiddisk to move relative to said inner edge of said opening to allow saidbimetal disk to flex according to temperature changes of the outsideair, said disk having a drain hole positioned approximately in thecenter thereof, said disk being flexed upwardly with respect to thebottom of said sump when the temperature of the outside air is above apredetermined temperature tzhereby maintaining said drain hole adistance above the bottom of the sump and retaining condensate water insaid sump, said disk being flexed downwardly with respect to the bottomof said sump when the temperature of the outside air is below apredetermined temperature so that said drain hole is disposed beneaththe level of the bottom of said sump to permit condensate water to drainthrough said drain hole.

4. In combination with a self-contained air conditioner having acondensate water collection sump exposed to outside temperatureconditions and including a rotatable Water slinger ring extending intosaid sump, drain means in the bottom of said sump comprising a thermallyresponsive disk mounted in an opening in the bottom of said sump withthe outer edge of said disk in water tight sealed relation with thebottom of said sump, said disk having a drain hole positionedapproximately in the center thereof, said disk being flexed upwardlywith respect to the bottom of said sump when the temperature of outsideair is above a predetermined temperature so that said drain hole ismaintained a distance above the lowest portion of said slinger ringextending into said sump, said disk being flexed downwardly with respectto the bottom of said sump when the temperature of the outside air isbelow a predetermined temperature so that said drain hole is disposedbeneath the level of the bottom of said sump to permit condensate waterto drain through said drain hole.

References Cited in the file of this patent UNITED STATES PATENTS1,558,276 Peterson Oct. 20, 1925 2,214,844 Van Kevren Sept. 17, 19402,777,303 Slattery Jan. 15, 1957 2,804,758 Smith Sept. 3, 1957

